scholarly journals First Assessment of the Benthic Meiofauna Sensitivity to Low Human-Impacted Mangroves in French Guiana

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 338
Author(s):  
Claire Michelet ◽  
Daniela Zeppilli ◽  
Cédric Hubas ◽  
Elisa Baldrighi ◽  
Philippe Cuny ◽  
...  
Keyword(s):  
South America ◽  
French Guiana ◽  
Ecological Status ◽  
Organic Enrichment ◽  
Strongly Correlated ◽  
Trophic Groups ◽  
Ecological State ◽  
Spatio Temporal ◽  
De Man ◽  
Main City

Bioindicators assess the mangroves ecological state according to the types of pressures but they differ with the ecosystem’s specificities. We investigated benthic meiofauna diversity and structure within the low human-impacted mangroves in French Guiana (South America) in response to sediment variables with various distances to the main city. Contaminant’s concentrations differed among the stations, but they remained below toxicity guidelines. Meiofauna structure (Foraminifera, Kinorhyncha, Nematoda) however varied accordingly. Nematode’s identification brought details on the sediment’s quality. The opportunistic genus Paraethmolaimus (Jensen, 1994) strongly correlated to the higher concentrations of Hg, Pb. Anoxic sediments were marked by organic enrichment in pesticides, PCB, and mangrove litter products and dominance of two tolerant genus, Terschellingia (de Man, 1888) and Spirinia (Gerlach, 1963). In each of these two stations, we found many Desmodora individuals (de Man, 1889) with the presence of epibionts highlighting the nematodes decreased fitness and defenses. Oxic sediments without contaminants were distinguished by the sensitive genera Pseudocella (Filipjev, 1927) and a higher diversity of trophic groups. Our results suggested a nematodes sensitivity to low contaminants concentrations. Further investigations at different spatio-temporal scales and levels of deterioration, would be necessary to use of this group as bioindicator of the mangroves’ ecological status.

scholarly journals Human Q Fever on the Guiana Shield and Brazil: Recent Findings and Remaining Questions

2021 ◽  
Author(s):  
Loïc Epelboin ◽  
Carole Eldin ◽  
Pauline Thill ◽  
Vincent Pommier de Santi ◽  
Philippe Abboud ◽  
...  
Keyword(s):  
South America ◽  
Geographical Distribution ◽  
Coxiella Burnetii ◽  
French Guiana ◽  
Q Fever ◽  
Guiana Shield ◽  
Animal Reservoir ◽  
The World ◽  
Unique Strain ◽  
Amazonian Region

Abstract Purpose of Review In this review, we report on the state of knowledge about human Q fever in Brazil and on the Guiana Shield, an Amazonian region located in northeastern South America. There is a contrast between French Guiana, where the incidence of this disease is the highest in the world, and other countries where this disease is practically non-existent. Recent Findings Recent findings are essentially in French Guiana where a unique strain MST17 has been identified; it is probably more virulent than those usually found with a particularly marked pulmonary tropism, a mysterious animal reservoir, a geographical distribution that raises questions. Summary Q fever is a bacterial zoonosis due to Coxiella burnetii that has been reported worldwide. On the Guiana Shield, a region mostly covered by Amazonian forest, which encompasses the Venezuelan State of Bolivar, Guyana, Suriname, French Guiana, and the Brazilian State of Amapá, the situation is very heterogeneous. While French Guiana is the region reporting the highest incidence of this disease in the world, with a single infecting clone (MST 117) and a unique epidemiological cycle, it has hardly ever been reported in other countries in the region. This absence of cases raises many questions and is probably due to massive under-diagnosis. Studies should estimate comprehensively the true burden of this disease in the region.

BIOSYSTEMATIC STUDIES ON XANTHIUM: TAXONOMIC APPRAISAL AND ECOLOGICAL STATUS

1959 ◽  
Vol 37 (2) ◽  
pp. 173-208 ◽  
Author(s):  
Doris Löve ◽  
Pierre Dansereau
Keyword(s):  
North America ◽  
South America ◽  
Ecological Status ◽  
Distinct Species ◽  
Eastern North America ◽  
Flowering Response ◽  
Short Day ◽  
Stable Species ◽  
Enormous Variation

The following paper is an evaluation of the taxonomic and ecological status of the genus Xanthium L. A review of its systematics demonstrates that many so-called "species" described on material from Europe actually have their origin in America, except one, X. strumarium s. str., which seems to have a Mediterranean–European center of dispersal. Another conclusion drawn is that Xanthium consists of only two distinct species: X. spinosum L. and X. strumarium L. The former is a relatively stable species, the latter an enormously variable one readily subdivided into a number of minor taxonomic entities.Ecologically, in eastern North America at least, Xanthium is primarily a beach plant, which prefers open habitats and succumbs to crowding. The seeds are most often dispersed by water and wind. It enters easily into ruderal habitats, but only as long as these are open and unshaded.The generalized short-day flowering response in this genus supports our hypothesis that Xanthium has a tropical–subtropical origin, and we feel that it has its center in Central and/or South America, whence it has spread over the continents north and southward.There is no evidence for any sterility barriers separating the entities of X. strumarium, but we feel that an intense inbreeding with an occasional outbreeding is responsible for the enormous variation, often resulting in small, local, but unstable taxa.

Xanthomonas campestris pv. vasculorum. [Distribution map].

1984 ◽  
Author(s):  
Keyword(s):  
South Africa ◽  
Puerto Rico ◽  
South America ◽  
Central America ◽  
West Indies ◽  
Xanthomonas Campestris ◽  
French Guiana ◽  
Saccharum Officinarum ◽  
Distribution Map ◽  
New Distribution

Abstract A new distribution map is provided for Xanthomonas campestris pv. vasculorum (Cobb) Dye. Hosts: Sugarcane (Saccharum officinarum). Information is given on the geographical distribution in AFRICA, Ghana, Madagascar, Madeira, Malawi, Mauritius, Mozambique, Reunion, South Africa (Natal), Swaziland, Zimbabwe, ASIA, AUSTRALASIA & OCEANIA, New Guinea, NORTH AMERICA, Mexico, CENTRAL AMERICA & WEST INDIES, Belize, Dominica, Dominican Republic, Panama, Puerto Rico, St. Kitts and Nevis, SOUTH AMERICA, Argentina (Tucuman), Brazil, Colombia, French Guiana.

Mycena citricolor. [Distribution map].

1975 ◽  
Author(s):  
Keyword(s):  
Puerto Rico ◽  
Costa Rica ◽  
North America ◽  
South America ◽  
Dominican Republic ◽  
Central America ◽  
West Indies ◽  
French Guiana ◽  
Distribution Map ◽  
New Distribution

Abstract A new distribution map is provided for Mycena citricolor (Berk. & Curt.) Sacc. Hosts: Coffee (Coffea spp.) and others. Information is given on the geographical distribution in NORTH AMERICA, Mexico, USA (Florida), CENTRAL AMERICA & WEST INDIES, Costa Rica, Cuba, Dominica, Dominican Republic, Guadeloupe, Guatemala, Haiti, Honduras, Jamaica, Martiniq, caragua, Panama, Puerto Rico, Salvador, Trinidad, SOUTH AMERICA, Brazil, Bolivia, Colombia, Ecuador, French, Guiana, Guyana, Peru, Surinam, Venezuela.

Typophorus nigritus. [Distribution map].

1991 ◽  
Author(s):  
Keyword(s):  
Costa Rica ◽  
South America ◽  
Central America ◽  
Sweet Potato ◽  
Geographical Distribution ◽  
French Guiana ◽  
Distribution Map ◽  
New Distribution

Abstract A new distribution map is provided for Typophorus nigritus (Fabricius) Coleoptera: Chrysomelidae, Eumolpinae. Attacks sweet-potato. Information is given on the geographical distribution in CENTRAL AMERICA and CARIBBEAN, Costa Rica, Cuba, Grenada, Grenadine Islands, Guatemala, Honduras, Mexico, Nicaragua, Panama, St. Vincent, Trinidad, SOUTH AMERICA, Argentina, Bolivia, Brazil, Colombia, Equador, French Guiana, Guyana, Paraguay, Peru, Uruguay, Venezuela.

Variability of gait spatio-temporal parameters during treadmill walking

2021 ◽  
Author(s):  
Miroslaw Latka ◽  
Klaudia Kozlowska ◽  
Bruce J. West
Keyword(s):  
Stride Length ◽  
Fundamental Problem ◽  
Treadmill Walking ◽  
Frequency Noise ◽  
Strongly Correlated ◽  
Nonlinear Functions ◽  
Mean Values ◽  
First Case ◽  
Gait Parameters ◽  
Spatio Temporal

Abstract During treadmill walking, the subject’s stride length (SL) and duration (ST) yield a stride speed (SS) which fluctuates over a narrow range centered on the treadmill belt’s speed. We recently demonstrated that ST and SL trends are strongly correlated and serve as control manifolds about which the corresponding gait parameters fluctuate. The fundamental problem, which has not yet been investigated, concerns the contribution of SL and ST fluctuations to SS variability. To investigate this relation, we approximate SS variance by the linear combination of SL variance and ST variance, as well as their covariance. The combination coefficients are nonlinear functions of ST and SL mean values and, consequently, depend on treadmill speed. The approximation applies to constant speed treadmill walking and walking on a treadmill whose belt speed is perturbed by strong, high-frequency noise. In the first case, up to 80% of stride speed variance comes from SL fluctuations. In the presence of perturbations, the SL contribution decreases with increasing speed, but its lowest value is still twice as large as that of either ST variance or SL-ST covariance. The presented evidence supports the hypothesis that stride length adjustments are primarily responsible for speed maintenance during walking. Such a control strategy is evolutionarily advantageous due to the weak speed dependence of the SL contribution to SS variance. The ability to maintain speed close to that of a moving cohort did increase the chance of an individual’s survival throughout most of human evolution.

scholarly journals Global horizontal irradiation: spatio-temporal variability on a regional scale in the south of the Pampeana region (Argentina)

2021 ◽  
Vol 56 (2) ◽  
pp. 220-233
Author(s):  
María Eugenia Fernández ◽  
Jorge Osvaldo Gentili ◽  
Ana Casado ◽  
Alicia María Campo
Keyword(s):  
South America ◽  
Seasonal Dynamics ◽  
Temporal Variability ◽  
Cloud Cover ◽  
Regional Scale ◽  
Temporal Distribution ◽  
The South ◽  
Monsoon System ◽  
Spatio Temporal ◽  
Dynamics Of Action

The objective of this work is to analyze the spatio-temporal distribution of Global Horizontal Irradiation (GHI) on a regional scale and its relationship with frequent synoptic situations in the south of the Pampeana region (Argentina). It was verified that the latitudinal pattern of distribution of the GHI is modified in the region by cloud cover, which is in turn determined by the seasonal dynamics of action centers and the passage of fronts in summer and winter. The South America Monsoon System (SAMS) defines differential situations of cloudiness and rainfall in the region, which affect GHI. GHI increased successively between the decades 1981–2010, a factor associated with the variability of rainfall that characterizes the region.

Diaprepes abbreviatus. [Distribution map].

1980 ◽  
Author(s):  
Keyword(s):  
North America ◽  
South America ◽  
Geographical Distribution ◽  
Sugar Cane ◽  
West Indies ◽  
Host Plants ◽  
French Guiana ◽  
Distribution Map ◽  
Diaprepes Abbreviatus ◽  
New Distribution

Abstract A new distribution map is provided for Diaprepes abbreviatus (L.) (Col., Curculionidae) (Citrus Weevil). Host Plants: Citrus, cassava, maize, sugar cane. Information is given on the geographical distribution in NORTH AMERICA, USA, WEST INDIES, SOUTH AMERICA, French Guiana.

Mycosyrinx cissi. [Distribution map].

1993 ◽  
Author(s):  
Keyword(s):  
Puerto Rico ◽  
North America ◽  
South America ◽  
Dominican Republic ◽  
Central America ◽  
Sierra Leone ◽  
West Indies ◽  
French Guiana ◽  
Distribution Map ◽  
New Distribution

Abstract A new distribution map is provided for Mycosyrinx cissi (DC.) G. Beck. Hosts: Cissus spp. Information is given on the geographical distribution in AFRICA, Congo, Ethiopia, Ghana, Guinea, Guinea, Nigeria, Sierra Leone, Tanzania, Uganda, Zaire, ASIA, India, Madras, Yemen, NORTH AMERICA, USA, Mexico, CENTRAL AMERICA & WEST INDIES, Bahamas, Belize, Costa Rica, Cuba, Dominica, Dominican Republic, Guatemala, Haiti, Honduras, Jamaica, Panama, Puerto Rico, St Croix, St Thomas, Trinidad, SOUTH AMERICA, Bolivia, Brazil, Colombia, Ecuador, French, Guiana, Guyana, Peru, Venezuela.

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